The Ministry of Defence said next of kin of both have been informed, and it is expected they will be named on Saturday.

The first death was that of a soldier from the Royal Electrical and Mechanical Engineers. The MoD said the death at Camp Bastion in Helmand province was not thought to be the result of hostile action, though an investigation into the circumstances is continuing.

The member of 104 Force Support Battalion was attached to 4 Close Support Battalion, Royal Electrical and Mechanical Engineers (REME).

Lieutenant Colonel Richard Parry, spokesman for Joint Force Support (Afghanistan), said: "The condolences of all personnel serving with Joint Force Support (Afghanistan) are with the soldier's family and friends at this extremely difficult time."

Later on Friday, the MoD announced the death of a soldier from 28 Engineer Regiment, attached to 21 Engineer Regiment at Forward Operating Base Shawqat, Helmand province.

A spokesman said: "The soldier was involved in a shooting incident at a forward operating base in the district of Nad-e Ali. A full investigation is ongoing and the circumstances are not being treated as a hostile action."

Spokesman for Task Force Helmand, Major Laurence Roche, said: "I am very sorry to report the death of a soldier serving with 21 Engineer Regiment who was involved in a shooting incident at Forward Operating Base Shawqat.

"This is a tragic day for everyone serving with Task Force Helmand in Afghanistan as we mourn this sad loss of life. Our thoughts are with the soldier's family and friends during their time of grief and loss."

The deaths bring the total number of members of UK forces to have died since operations in Afghanistan began in October 2001 to 432.